Add LSP call hierarchy modal

[swiftcoder]

Closes #14203

Release Notes:

• Initial Call Hierarchy support in Zed

[swiftcoder]

I've been rebasing this change for about a month - what's the chance we can get some discussion going about whether this is the right approach, and what we'd need to do to get it merged?

[alexpana]

I wanted to pick this up myself, incredibly disappointing that there's no discussion over it.

[smitbarmase]

Thanks for working on this. Do you think it would be possible to split this PR into a few smaller, more focused chunks?

This is a fairly large change, which makes it difficult to review in one go. Breaking it down would give us a better path toward landing the changes incrementally.

[swiftcoder]

I can split this into a stack of changes if it helps, but 90% of the review is going to be lsp_command.rs and lsp_store.rs either way. The rest is pretty much all boilerplate (panel layout, settings, etc)

[swiftcoder]

@smitbarmase I don't have the necessary access to upstream stacked PRs, so I've sent the first one upstream, and stacked the rest in my fork. Appreciated if you could advise on the best way to get these in front of your team:

#60885
swiftcoder#3
swiftcoder#4
swiftcoder#5
swiftcoder#6

[SomeoneToIgnore]

Thank you a lot for the work and sorry for such late review: hoped that the original opinions could be discussed with the person who had them.

I think I can pick it up from here, but welcome to add more input if you want to, or test it.
One major decision made for now is to remove the new panel: diff is way smaller and more focused, way less UI design concerns, etc. etc.
We can land it later after polish the main functionality.

[swiftcoder]

Happy to see movement on this! Let me know if there is anything I can do to help

[SomeoneToIgnore]

Thank you, I would appreciate some testing, any time you feel like it and once before the actual merge: the idea is to have no flickering/odd text trimming, etc. usability issues.

[SomeoneToIgnore]

Hey @swiftcoder — I think I am over with the polish.
As stated, unfortunately, this branch won't include the panel as another huge chunk of work and, most importantly, design (that I cannot provide as good as the code changes).

Hopefully this lies grounds for the further work — would appreciate if you can test it and report anything that you find odd or buggy: posting here or creating new issues, anything goes.

Have been using it for some time and seems like a good start to me, hence will merge.

Thanks a lot for you patience with all this!